A voltmeter is used to measure the electrical potential difference (voltage) between two points in a circuit. It is connected in parallel with the component whose voltage is to be measured. The unit of voltage is the volt (V).
Which of these components limits current in a circuit?
A Capacitor
B Battery
C Resistor
D Inductor
A resistor is a component that limits the flow of current in a circuit. It provides resistance to the electrical current, which helps to control the current and protect sensitive components from overload.
What is the function of a transformer in an electrical system?
A Store energy
B Change voltage
C Measure resistance
D Change current
A transformer is used to change the voltage in an AC circuit, either stepping it up or stepping it down. It operates on the principle of electromagnetic induction, where the voltage is changed depending on the coil turns ratio.
Which of the following is a unit of power?
A Volt
B Ampere
C Watt
D Ohm
The unit of electrical power is the watt (W). Power is the rate at which electrical energy is used or generated. One watt equals one joule per second. Power is calculated as the product of voltage and current.
Which component stores electrical energy in the form of an electric field?
A Capacitor
B Resistor
C Inductor
D Transformer
A capacitor stores electrical energy in the form of an electric field between two conductive plates separated by an insulating material. It can release the stored energy when required and is widely used in filtering applications.
What is the purpose of grounding an electrical system?
A Increase power
B Store charge
C Protect from shocks
D Reduce voltage
Grounding an electrical system provides a safe path for electric current to flow to the earth. It helps prevent electric shocks by ensuring that any stray current flows into the ground rather than through a person’s body.
What unit measures electric current?
A Ampere
B Watt
C Volt
D Ohm
The unit of electric current is the ampere (A). Current represents the flow of electric charge through a conductor, and it is measured as the amount of charge passing a point in one second.
Which device is used to measure resistance?
A Ammeter
B Volt
C Wattmeter
D Ohmmeter
An ohmmeter is used to measure the resistance of a component or circuit. It works by passing a small current through the resistor and measuring the voltage drop to calculate resistance, which is measured in ohms (Ω).
What is the unit of electrical conductance?
A Ohm
B Volt
C Siemens
D Ampere
The unit of electrical conductance is siemens (S). Conductance is the inverse of resistance, indicating how easily current can flow through a conductor. A higher conductance means lower resistance and better current flow.
What is the primary function of an inductor in a circuit?
A To store energy
B To limit current
C To measure voltage
D To store charge
An inductor stores energy in the form of a magnetic field when current flows through it. It resists changes in current and is used in applications such as filters, inductive heating, and energy storage.
Which type of current flows in only one direction?
A AC
B DC
C Pulsating
D Reactive
Direct current (DC) flows in only one direction, from the positive to the negative terminal. It is commonly used in batteries and electronic devices. In contrast, alternating current (AC) periodically reverses direction.
What is the relationship between voltage, current, and resistance called?
A Coulomb’s Law
B Kirchhoff’s Law
C Ohm’s Law
D Faraday’s Law
Ohm’s Law describes the relationship between voltage (V), current (I), and resistance (R) in an electrical circuit. It states that voltage equals the product of current and resistance, or V = I * R.
Which device is used to protect an electrical circuit from overcurrent?
A Fuse
B Transformer
C Capacitor
D Inductor
A fuse is a protective device that interrupts the current flow when it exceeds a safe limit. It contains a wire that melts under excessive current, breaking the circuit and preventing further damage to the components.
What is the function of a battery in a circuit?
A To store voltage
B To provide energy
C To store current
D To measure resistance
A battery stores chemical energy and converts it into electrical energy when connected to a circuit. This energy is provided as direct current (DC) to power devices. Batteries are commonly used in portable applications.
What is the main characteristic of an ohmic conductor?
A Constant resistance
B Variable resistance
C Nonlinear behavior
D Does not conduct
An ohmic conductor follows Ohm’s Law, meaning its resistance remains constant over a range of voltages and currents. This characteristic is typical of materials like metals (e.g., copper) that conduct electricity linearly.